I agree and disagree with this topic in equal measure.
There are so many cover bands out there which are terrible. But I have seen some absolutely quality cover bands who spend hours and hours perfecting the songs they play. They are tailor made and put together with passion. And they earn a fortune.
Its not all about money some people say, but will and passion alone doesn't pay bills. Plus if you are in a great cover band, its really fun.
On the flip side, I love live original music. But as someone has already said, the average pub going punter, doesn't want to hear two hours of original material. Unless its top quality. But like someone has also said, a good song is equal parts music and good songwriting. So many bands write poor songs and label them top quality.
Hence why cover bands get more gigs. This is my opinion but the sorry truth of it. It's a lot easier to work 5 nights a week playing covers than it is playing original material.
My solution: Be in a great cover band which pays the bills which funds original material. Once original material starts paying money and fuels ambition, ditch the covers